Coherent Population Trapping of Electron Spins in a Semiconductor

In high-purity n-type GaAs under strong magnetic field, we are able to isolate a lambda system composed of two Zeeman states of neutral-donor bound electrons and the lowest Zeeman state of bound excitons. When the two-photon detuning of this system is zero, we observe a pronounced dip in the excited-state photoluminescence indicating the creation of the coherent population-trapped state. Our data are consistent with a steady-state three-level density-matrix model. The observation of coherent population trapping in GaAs indicates that this and similar semiconductor systems could be used for various EIT-type experiments.Comment: 5 pages, 4 figures replaced 6/25/2007 with PRL versio

Maritime Strategy and the Pacific: The Implications for NATO

Ambitious in its purpose, this article seeks to explore the implications for NATO of developments in the Pacific-both in the near term and the far term, and both in peace and in the case of a major failure of deterrence, in war

The Coast Guard and Navy

The U.S. Navy and the Coast Guard are natural complements, and this complementarity should be expressed practically, in a “national fleet” that is not mere rhetoric. The argument is new, but it is well established in historical practice. What should the Navy and Coast Guard do to aid each other

Defense, War-Fighting and Deterrence

Having been in retreat through most of the 1970s, the advocates of a mutual assured destruction approach to nuclear deterrence and force planning are staging something of a comeback